SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 3)
   ExpressionList (children 1)
    Function mapConcat (children 1)
     ExpressionList (children 3)
      Identifier col
      Function materialize (children 1)
       ExpressionList (children 1)
        Function map (children 1)
         ExpressionList (children 2)
          Literal \'key5\'
          Literal UInt64_500
      Function map (children 1)
       ExpressionList (children 2)
        Literal \'key6\'
        Literal UInt64_600
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier table_map
   ExpressionList (children 1)
    OrderByElement (children 1)
     Identifier id